CN202422725U - Audio signal processing circuit - Google Patents
Audio signal processing circuit Download PDFInfo
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- CN202422725U CN202422725U CN2012200090911U CN201220009091U CN202422725U CN 202422725 U CN202422725 U CN 202422725U CN 2012200090911 U CN2012200090911 U CN 2012200090911U CN 201220009091 U CN201220009091 U CN 201220009091U CN 202422725 U CN202422725 U CN 202422725U
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Abstract
The utility model discloses an audio signal processing circuit. The audio signal processing circuit is characterized by consisting of a low-pass filter, a half-period amplifier, a peak detector, a differential amplifier and a valley value signal extraction circuit, wherein the low-pass filter acquires audio signals; the half-period amplifier performs half-period rectification and amplification on the signals; the peak detector acquires envelope line signals of half-period signals and transmits the envelope line signals to a non-inverting input end of the differential amplifier; the envelope line signals are also transmitted to the valley value signal extraction circuit, so that the valley value envelop lines of the envelope line signals are extracted and transmitted to an inverting input end of the differential amplifier; and the differential amplifier performs differential amplification on the non-inverting and inverting signals, and finally outputs amplitude variation values of the audio signals. The significant advantages are that the audio signal processing circuit is simple in structure and easy to implement, is specially used for processing audio signals in music, and eliminates direct-current components in the audio signals, and output amplitude variation signals have a large dynamic range to meet application requirements of various sound control lighting decorations.
Description
Technical field
The utility model relates to signal processing technology, specifically, is a kind of audio signal processing circuit.
Background technology
Urban landscape is made up of light and music usually, and in order to increase aesthetic of city, in the control procedure, the variation of light need match with the fluctuations of main rhythm in the music.Therefore, in voice-operated device, often need a kind of audio signal processing circuit, it can gather music signal, and the sound signal in the music is handled, and takes out the amplitude variable signal of sound signal, thereby realizes the acousto-optic synchro control.
Existing audio signal processing circuit is directed against speech processes often, owing to the audio signal frequency in voice signal frequency and the music there are differences, and generally speaking can not be general.And existing Audio Signal Processing often all is to adopt envelope detection circuit to detect the envelope variation of sound signal, has certain DC component, if directly be transferred to the sound Synchronizing Control Devices, opertaing device can not reach maximum dynamic range.
The utility model content
The purpose of the utility model provides a kind of audio signal processing circuit; The special audio frequency range that is directed against in the music is handled; And the DC component in the removal sound signal, make its amplitude variable have bigger dynamic range, therefore satisfy the application demand of acoustic control lamp decoration.
For achieving the above object, the technical scheme that the utility model adopted is:
A kind of audio signal processing circuit; Its key is: be made up of low-pass filter, half cycle amplifier, peak detector, differential amplifier and valley signal extracting circuit; The input end of said low-pass filter is brought in the audio frequency acquiring signal as picking up signal; This sound signal is sent in the said half cycle amplifier through behind the said low-pass filter; This half cycle amplifier carries out half cycle rectification and amplification with the signal that receives, and exports the half cycle signal then in said peak detector, and this peak detector obtains the envelope signal of said half cycle signal and this envelope signal sent into the normal phase input end of said differential amplifier; This envelope signal is also sent in the said valley signal extracting circuit; This valley signal extracting circuit extracts the valley envelope of said envelope signal and this valley envelope is sent into the inverting input of said differential amplifier, and said differential amplifier carries out difference with positive and negative two paths of signals and amplifies the changes in amplitude value of last output audio signal.
Said low-pass filter is made up of amplifier OP1, capacitor C 1, resistance R 2 and resistance R 5; One end of said resistance R 2 is as the picking up signal end; The other end of this resistance R 2 connects the inverting input of said amplifier OP1, the positive input end grounding of this amplifier OP1, the said capacitor C 1 of serial connection between the inverting input of said amplifier OP1 and output terminal; In the said resistance R 5 of the two ends of this capacitor C 1 parallel connection, the output terminal of said amplifier OP1 is the output terminal of this low-pass filter.
Through spectrum analysis; Because the fluctuating of sound signal master's rhythm of most of music is mainly reflected in the amplitude of low-band signal; In order to reach the better sound synchronous effect, amplifier OP1, capacitor C 2, resistance R 2 and resistance R 5 are formed low-pass filter, promote the low frequency part in the sound signal.
Said half cycle amplifier is made up of resistance R 1, diode D1, amplifier OP2 and resistance R 3 and resistance R 4; One end of said resistance R 1 is as this half cycle amplifier input terminal; The other end of this resistance R 1 connects the normal phase input end of said amplifier OP2, and the other end of said resistance R 1 also links to each other with the negative pole of said diode D1, the plus earth of this diode D1; The inverting input of said amplifier OP2 is connected with an end of said resistance R 3; The other end ground connection of this resistance R 3 also is connected in series said resistance R 4 between the inverting input of amplifier OP2 and output terminal, the output terminal of said amplifier OP2 is the output terminal of this half cycle amplifier.
Resistance R 1 is formed the half cycle rectifier with diode D1, when the voltage of input end greater than ground voltage, diode D1 ends, the positive half cycle of input signal gets into amplifier OP2 in-phase input end through resistance R 1, the gain of resistance R 3 and resistance R 4 control amplifier OP2.
Said peak detector is made up of resistance R 6, diode D2, resistance R 8 and capacitor C 2; One end of said resistance R 6 is the input end of this peak detector, and the other end of this resistance R 6 is connected with the positive pole of said diode D2, and the negative pole of this diode D2 is connected with an end of said resistance R 8; The other end ground connection of this resistance R 8; The negative pole of said diode D2 also is connected with an end of said capacitor C 2, the other end ground connection of this capacitor C 2, and an end of said capacitor C 2 is the output terminal of this peak detector.
In peak detector; The resistance of resistance R 6 need be far longer than resistance R 8; When the positive half cycle of a sound signal is imported; Signal makes capacitor C 2 quickly charge to PV through resistance R 6 with diode D2, and capacitor C 2 made the envelope signal of its output audio half cycle signal through resistance R 8 discharges after signal reached peak value.
According to different demands, said capacitor C 2 is formed discharge circuit with resistance R 8, and its time constant is 30ms～100ms, thereby obtains significantly audio frequency fluctuating effect.
Said valley signal extracting circuit is made up of amplifier OP4, diode D3, resistance R 10, capacitor C 3 and resistance R 9; The normal phase input end of said amplifier OP4 is the input end of this valley signal extracting circuit; The inverting input of this amplifier OP4 is connected with output terminal; The output terminal of this amplifier OP4 links to each other with said diode D3 negative pole, and the positive pole of this diode D3 is connected with an end of said resistance R 10, the other end ground connection of this resistance R 10; The positive pole of this diode D3 also is connected with an end of said capacitor C 3; Another termination positive source V+ of this capacitor C 3, the positive pole of this diode D3 also links to each other with an end of said resistance R 9, and the other end of resistance R 9 is the output terminal of this valley signal extracting circuit.
The signal of input extracts the signal valley through amplifier OP4 buffering back by diode D3 and capacitor C 3; When amplifier OP4 output voltage is higher than the voltage of diode D3 positive terminal; Diode D3 ends; Capacitor C 3 is slowly discharged through resistance R 10, and capacitor C 3 is generally got more than the 1S with resistance R 10 time constants, thus the valley envelope of output signal.
Said differential amplifier is made up of amplifier OP3, resistance R 7 and variable resistor W1; The normal phase input end of said amplifier OP3 is connected with the output terminal of said peak detector; The inverting input of said amplifier OP3 is connected with the output terminal of said valley signal extracting circuit; The said resistance R 7 of serial connection between the inverting input of amplifier OP3 and output terminal; The output terminal of this amplifier OP3 is connected with the stiff end of said variable resistor W1, another stiff end ground connection of this variable resistor W1, and the sliding end of this variable resistor W1 is the changes in amplitude value of signal output part output audio signal.
Frequency range according to music sound intermediate frequency signal confirms that the cutoff frequency of said low-pass filter is 200Hz～500Hz.
The remarkable result of the utility model is: circuit structure is simple; Realize easily; The special sound signal that is directed against in the music is handled, and has removed the DC component in the sound signal, and the amplitude variable signal of output has bigger dynamic range; Satisfy the application demand of various acoustic control lamp decorations, realize the acousto-optic synchronous effect.
Description of drawings
Fig. 1 is the schematic block circuit diagram of the utility model;
Fig. 2 is the circuit theory diagrams of the utility model;
Fig. 3 is the audio input signal waveform;
Fig. 4 is an audio frequency half cycle signal waveform;
Fig. 5 is an audio pack winding thread signal waveform;
Fig. 6 is the valley signal waveform of audio pack winding thread;
Fig. 7 is an audio frequency signal amplitude variable signal waveform.
Embodiment:
Below in conjunction with accompanying drawing the utility model is further described.
As shown in Figure 1; A kind of audio signal processing circuit; Form by low-pass filter 1, half cycle amplifier 2, peak detector 3, differential amplifier 4 and valley signal extracting circuit 5; The input end of said low-pass filter 1 is brought in the audio frequency acquiring signal as picking up signal, and this sound signal is sent in the said half cycle amplifier 2 through behind the said low-pass filter 1, and this half cycle amplifier 2 carries out half cycle rectification and amplification with the signal that receives; Export the half cycle signal then in said peak detector 3; This peak detector 3 obtains the envelope signal of said half cycle signal and this envelope signal is sent into the normal phase input end of said differential amplifier 4, and this envelope signal is also sent in the said valley signal extracting circuit 5, and this valley signal extracting circuit 5 extracts the valley envelope of said envelope signal and this valley envelope sent into the inverting input of said differential amplifier 4; Said differential amplifier 4 carries out difference with positive and negative two paths of signals and amplifies the changes in amplitude value of last output audio signal.
As shown in Figure 2, in the practical implementation process, said low-pass filter 1 is made up of amplifier OP1, capacitor C 1, resistance R 2 and resistance R 5; One end of said resistance R 2 is as the picking up signal end; The other end of resistance R 2 connects the inverting input of amplifier OP1, the positive input end grounding of amplifier OP1, serial connection capacitor C 1 between the inverting input of amplifier OP1 and output terminal; In the said resistance R 5 of the two ends of capacitor C 1 parallel connection, the output terminal of said amplifier OP1 is the output terminal of this low-pass filter 1.
Said half cycle amplifier 2 is made up of resistance R 1, diode D1, amplifier OP2 and resistance R 3 and resistance R 4; One end of said resistance R 1 is as the input end of this half cycle amplifier 2; The other end of this resistance R 1 connects the normal phase input end of said amplifier OP2, and the other end of said resistance R 1 also links to each other with the negative pole of said diode D1, the plus earth of this diode D1; The inverting input of said amplifier OP2 is connected with an end of said resistance R 3; The other end ground connection of this resistance R 3 also is connected in series said resistance R 4 between the inverting input of amplifier OP2 and output terminal, the output terminal of said amplifier OP2 is the output terminal of this half cycle amplifier 2.
Said peak detector 3 is made up of resistance R 6, diode D2, resistance R 8 and capacitor C 2; One end of said resistance R 6 is the input end of this peak detector 3; The other end of this resistance R 6 is connected with the positive pole of said diode D2; The negative pole of this diode D2 is connected with an end of said resistance R 8, the other end ground connection of this resistance R 8, and the negative pole of said diode D2 also is connected with an end of said capacitor C 2; The other end ground connection of this capacitor C 2, an end of said capacitor C 2 is the output terminal of this peak detector 3.
According to different demands, said capacitor C 2 is formed discharge circuit with resistance R 8, and its time constant is 30ms～100ms, thereby obtains significantly audio frequency fluctuating effect.
Said valley signal extracting circuit 5 is made up of amplifier OP4, diode D3, resistance R 10, capacitor C 3 and resistance R 9; The normal phase input end of said amplifier OP4 is the input end of this valley signal extracting circuit 5; The inverting input of this amplifier OP4 is connected with output terminal; The output terminal of this amplifier OP4 links to each other with said diode D3 negative pole, and the positive pole of this diode D3 is connected with an end of said resistance R 10, the other end ground connection of this resistance R 10; The positive pole of this diode D3 also is connected with an end of said capacitor C 3; Another termination positive source V+ of this capacitor C 3, the positive pole of this diode D3 also links to each other with an end of said resistance R 9, and the other end of resistance R 9 is the output terminal of this valley signal extracting circuit 5.
Said differential amplifier 4 is made up of amplifier OP3, resistance R 7 and variable resistor W1; The normal phase input end of said amplifier OP3 is connected with the output terminal of said peak detector 3; The inverting input of said amplifier OP3 is connected with the output terminal of said valley signal extracting circuit 5; The said resistance R 7 of serial connection between the inverting input of amplifier OP3 and output terminal; The output terminal of this amplifier OP3 is connected with the stiff end of said variable resistor W1, another stiff end ground connection of this variable resistor W1, and the sliding end of this variable resistor W1 is the changes in amplitude value of signal output part output audio signal.
The principle of work of the utility model is:
Like Fig. 3-shown in Figure 7; Because the fluctuating of sound signal master's rhythm of most of music is mainly reflected in the amplitude of low-band signal, in order to reach the better sound synchronous effect, amplifier OP1, capacitor C 2, resistance R 2 and resistance R 5 are formed low-pass filter 1; Promote the low frequency part in the sound signal; The frequency range of combining music sound intermediate frequency signal, the cutoff frequency of said low-pass filter 1 are 200Hz～500Hz, and 400Hz is optimum.
Sound signal shown in Figure 3 gets into the half cycle amplifier 2 from a point through low-pass filter 1 back; Because resistance R 1 is formed the half cycle rectifier with diode D1; When the voltage of input end greater than ground voltage, diode D1 ends, the positive half cycle of input signal gets into amplifier OP2 in-phase input end through resistance R 1; The gain of amplifier OP2 is by resistance R 3 and resistance R 4 controls, so c point output audio frequency half cycle signal shown in Figure 4.
Audio frequency half cycle signal shown in Figure 4 gets into the peak detector 3 from the c point; Because the resistance of resistance R 6 is far longer than resistance R 8; When the positive half cycle of a sound signal is imported; Signal makes capacitor C 2 quickly charge to PV through resistance R 6 with diode D2, and capacitor C 2 made the d point export the envelope signal of audio frequency half cycle signal shown in Figure 5 through resistance R 8 discharges after signal reached peak value.
Envelope signal shown in Figure 5 is from d point output, because when playing a continuous music, the amplitude envelops line of sound signal can not hang down ground level; And certain DC component is arranged, if signal directly is transferred to the sound Synchronizing Control Devices, opertaing device can not reach maximum dynamic range; For removing the DC component of d point output signal, the signal of d point output is divided into two-way and is input to amplifier OP3 and amplifier OP4 respectively, and one road signal of d point output extracts the signal valley through amplifier OP4 buffering back by diode D3 and capacitor C 3; When amplifier OP4 output voltage is higher than the voltage of diode D3 positive terminal; Diode D3 ends, and capacitor C 3 is slowly discharged through resistance R 10, and capacitor C 3 is generally got more than the 1S with resistance R 10 time constants; Thereby at the valley envelope of e point output signal, the waveform of e point output signal is as shown in Figure 6.
Another road signal of d point output is sent to the normal phase input end of amplifier OP3, and amplifier OP3 is one a differential amplifier, and the d point is the positive input; The e point is the anti-phase input, and the signal of e point output is a d point output signal valley envelope, therefore; The signal of amplifier OP3 output is Vo=(Vd-Ve) * G, and wherein Vo is an amplifier OP3 output signal voltage, and Vd is a d point output voltage of signals; Ve is an e point output voltage of signals, and G is the gain of amplifier OP3, and gain is by resistance R 7 and resistance R 9 decisions; Because the output signal is that d point signal and its valley envelope signal subtract each other, so amplifier OP3 removed the DC component of d point signal, only export the value of an audio frequency signal amplitude variation; As shown in Figure 7, the dynamic range of this value is bigger, satisfies the application demand of various acoustic control lamp decorations.
Claims (8)
1. audio signal processing circuit; It is characterized in that: form by low-pass filter (1), half cycle amplifier (2), peak detector (3), differential amplifier (4) and valley signal extracting circuit (5); The input end of said low-pass filter (1) is brought in the audio frequency acquiring signal as picking up signal; Send in the said half cycle amplifier (2) behind this sound signal said low-pass filter of process (1); This half cycle amplifier (2) carries out half cycle rectification and amplification with the signal that receives; Export the half cycle signal then in said peak detector (3); This peak detector (3) obtains the envelope signal of said half cycle signal and this envelope signal is sent into the normal phase input end of said differential amplifier (4), and this envelope signal is also sent in the said valley signal extracting circuit (5), and this valley signal extracting circuit (5) extracts the valley envelope of said envelope signal and this valley envelope sent into the inverting input of said differential amplifier (4); Said differential amplifier (4) carries out difference with positive and negative two paths of signals and amplifies the changes in amplitude value of last output audio signal.
2. audio signal processing circuit according to claim 1; It is characterized in that: said low-pass filter (1) is made up of amplifier OP1, capacitor C 1, resistance R 2 and resistance R 5; One end of said resistance R 2 is as the picking up signal end; The other end of this resistance R 2 connects the inverting input of said amplifier OP1, the positive input end grounding of this amplifier OP1, the said capacitor C 1 of serial connection between the inverting input of said amplifier OP1 and output terminal; In the said resistance R 5 of the two ends of this capacitor C 1 parallel connection, the output terminal of said amplifier OP1 is the output terminal of this low-pass filter (1).
3. audio signal processing circuit according to claim 1; It is characterized in that: said half cycle amplifier (2) is made up of resistance R 1, diode D1, amplifier OP2 and resistance R 3 and resistance R 4; One end of said resistance R 1 is as the input end of this half cycle amplifier (2); The other end of this resistance R 1 connects the normal phase input end of said amplifier OP2, and the other end of said resistance R 1 also links to each other with the negative pole of said diode D1, the plus earth of this diode D1; The inverting input of said amplifier OP2 is connected with an end of said resistance R 3; The other end ground connection of this resistance R 3 also is connected in series said resistance R 4 between the inverting input of amplifier OP2 and output terminal, the output terminal of said amplifier OP2 is the output terminal of this half cycle amplifier (2).
4. audio signal processing circuit according to claim 1; It is characterized in that: said peak detector (3) is made up of resistance R 6, diode D2, resistance R 8 and capacitor C 2; One end of said resistance R 6 is the input end of this peak detector (3), and the other end of this resistance R 6 is connected with the positive pole of said diode D2, and the negative pole of this diode D2 is connected with an end of said resistance R 8; The other end ground connection of this resistance R 8; The negative pole of said diode D2 also is connected with an end of said capacitor C 2, the other end ground connection of this capacitor C 2, and an end of said capacitor C 2 is the output terminal of this peak detector (3).
5. audio signal processing circuit according to claim 4 is characterized in that: said capacitor C 2 is formed discharge circuit with resistance R 8, and its time constant is 30ms～100ms.
6. audio signal processing circuit according to claim 1; It is characterized in that: said valley signal extracting circuit (5) is made up of amplifier OP4, diode D3, resistance R 10, capacitor C 3 and resistance R 9; The normal phase input end of said amplifier OP4 is the input end of this valley signal extracting circuit (5), and the inverting input of this amplifier OP4 is connected with output terminal, and the output terminal of this amplifier OP4 links to each other with said diode D3 negative pole; The positive pole of this diode D3 is connected with an end of said resistance R 10; The other end ground connection of this resistance R 10, the positive pole of this diode D3 also is connected with an end of said capacitor C 3, another termination positive source V+ of this capacitor C 3; The positive pole of this diode D3 also links to each other with an end of said resistance R 9, and the other end of resistance R 9 is the output terminal of this valley signal extracting circuit (5).
7. audio signal processing circuit according to claim 1; It is characterized in that: said differential amplifier (4) is made up of amplifier OP3, resistance R 7 and variable resistor W1; The normal phase input end of said amplifier OP3 is connected with the output terminal of said peak detector (3); The inverting input of said amplifier OP3 is connected with the output terminal of said valley signal extracting circuit (5); The said resistance R 7 of serial connection between the inverting input of amplifier OP3 and output terminal; The output terminal of this amplifier OP3 is connected with the stiff end of said variable resistor W1, another stiff end ground connection of this variable resistor W1, and the sliding end of this variable resistor W1 is the changes in amplitude value of signal output part output audio signal.
8. audio signal processing circuit according to claim 1 is characterized in that: the cutoff frequency of said low-pass filter (1) is 200Hz～500Hz.
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| Application Number | Priority Date | Filing Date | Title |
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| CN2012200090911U CN202422725U (en) | 2012-01-06 | 2012-01-06 | Audio signal processing circuit |
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| Application Number | Priority Date | Filing Date | Title |
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| CN2012200090911U CN202422725U (en) | 2012-01-06 | 2012-01-06 | Audio signal processing circuit |
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| CN202422725U true CN202422725U (en) | 2012-09-05 |
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| CN106162410A (en) * | 2016-08-16 | 2016-11-23 | 歌尔股份有限公司 | A kind of noise cancelling headphone |
| US9529023B2 (en) | 2014-12-16 | 2016-12-27 | Asustek Computer Inc. | Signal analysis circuit and signal analysis method thereof |
| CN106331947A (en) * | 2015-06-30 | 2017-01-11 | 展讯通信（上海）有限公司 | Coding and decoding chip and method for removing DC level of microphone |
| CN106332378A (en) * | 2016-11-26 | 2017-01-11 | 湖南人文科技学院 | Intelligent flickering LED lamp based on music rhythm identification and control method of intelligent flickering LED lamp |
| CN106656363A (en) * | 2016-12-02 | 2017-05-10 | 昆明理工大学 | Parameter extraction circuit for broadcast supervision receiver and parameter extraction method thereof |
| CN108020741A (en) * | 2017-11-30 | 2018-05-11 | 广东电网有限责任公司电力科学研究院 | A kind of double frequency harmonic attenuation signal damping characteristic recognition method and device |
| CN112382312A (en) * | 2020-09-23 | 2021-02-19 | 福建信通慧安科技有限公司 | Object detector and object detection method |
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2012
- 2012-01-06 CN CN2012200090911U patent/CN202422725U/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9529023B2 (en) | 2014-12-16 | 2016-12-27 | Asustek Computer Inc. | Signal analysis circuit and signal analysis method thereof |
| CN106331947A (en) * | 2015-06-30 | 2017-01-11 | 展讯通信（上海）有限公司 | Coding and decoding chip and method for removing DC level of microphone |
| CN106162410A (en) * | 2016-08-16 | 2016-11-23 | 歌尔股份有限公司 | A kind of noise cancelling headphone |
| CN106332378A (en) * | 2016-11-26 | 2017-01-11 | 湖南人文科技学院 | Intelligent flickering LED lamp based on music rhythm identification and control method of intelligent flickering LED lamp |
| CN106656363A (en) * | 2016-12-02 | 2017-05-10 | 昆明理工大学 | Parameter extraction circuit for broadcast supervision receiver and parameter extraction method thereof |
| CN106656363B (en) * | 2016-12-02 | 2020-07-31 | 昆明理工大学 | Parameter extraction circuit of broadcast monitoring receiver and parameter extraction method thereof |
| CN108020741A (en) * | 2017-11-30 | 2018-05-11 | 广东电网有限责任公司电力科学研究院 | A kind of double frequency harmonic attenuation signal damping characteristic recognition method and device |
| CN112382312A (en) * | 2020-09-23 | 2021-02-19 | 福建信通慧安科技有限公司 | Object detector and object detection method |
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